You can tidy up your Teams workspace by hiding channels or teams that are not important to your work at the moment.
To hide a channel or team, click the three-dot icon to the right of its name, then click Hide from the menu that opens. (Note that you cannot hide the General channel for any team.)
To unhide a channel, look at the list of channels under a team name. At the end of this list is a link saying how many hidden channels that this team has; click this link to open a menu revealing the hidden channels. Move the pointer over the name of the channel that you want to unhide, and click the Show icon to the right.
To unhide a team, look or scroll down to the end of the list of your teams, where you’ll see a Hidden teams link. Click this to open the list of hidden teams. Click the three-dot icon to the right of a hidden team, then click Show at the top of the menu that opens.